Hi allneed to replace the outer chainring on my R600 compact crankset. Is it worthwhile just buying the chainring, or replacing the whole chainset with 105 to match the rest of the bikes 105 components?

The R600 ring is around $70 but can get a 105 compact chainset for $135 plus delivery.

Anything else I'd need to consider if I take the upgrade option. I have 2009 Avanti Cadent 1.0 with press fit BB.

Still has the original chainset so about 12,000 klm at a guess. Outer chainring is well worn, inside not so bad as doesn't get a lot of use being compact.

Chain and cassette are still good, replaced not long ago, though a new chain is probably a good idea to mesh with the new chain rings.

EDIT: Just checked my maintenance records and BB, chain and cassette have around 1500 klm on them. Made me realize how slack I've been this year, but have a knee injury which requires surgery, and been riding my MTB to work. Excuses Excuses

My r700 crankset shaft has extensive wear. I think this is because the rubber seal on the non drive side was not there and water has got in and corroded the shaft.

If this happens, your non-side crank will start to wobble. the only solution I could find was to take out the pastic clip on the non-drive crank and tighten the hell out of the crank. This wont work forever and it will need replacing.